Apparatus and relative method for wrapping reams of paper

ABSTRACT

An apparatus for wrapping reams of paper in which the units for forming the first tube are adjacent to the devices for lateral folding of the first tube in order simultaneously to form lateral flaps.

[0001] The present invention relates to an apparatus and a method forwrapping reams of paper.

BACKGROUND OF THE INVENTION

[0002] As is known, an apparatus for wrapping reams of paper generallycomprises:

[0003] (a) a unit for forming and feeding the reams along a path;

[0004] (b) units for forming the first tube for wrapping of the ream ofpaper with a wrapping sheet;

[0005] (c) devices for the lateral folding of the first tube in order toform lateral flaps so as to obtain two lower tongues and two uppertongues;

[0006] (d) folding devices for the upper tongues;

[0007] (e) spray devices adapted to spray an adhesive substance on theinner surfaces of the lower tongues;

[0008] (f) devices for folding the lower tongues over the respectiveupper tongues, already folded, in order to obtain a pack containing theream.

[0009] Apparatus of this type have the drawback, however, that they arenot very compact and are not adapted to process reams of small format.

SUMMARY OF THE INVENTION

[0010] The object of the present invention is therefore to provide anapparatus and a relative method for wrapping a ream of paper which isfree from the drawbacks described above.

[0011] The apparatus of the present invention is therefore characterisedin that the units for forming the first tube are adjacent to the devicesfor the lateral folding of this first tube in order simultaneously toform the lateral flaps.

[0012] The present invention therefore relates principally to anapparatus for wrapping reams of paper in accordance with thecharacteristic features claimed in claim 1.

[0013] A further object of the present invention is a novel method forwrapping reams of paper in accordance with the characteristic featuresclaimed in claim 10.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present invention will be described below with reference tothe accompanying drawings which show a non-limiting embodiment thereofand in which:

[0015]FIG. 1 is a side view of an overall unit of the apparatus of thepresent invention in a first phase of operations for wrapping a ream ofpaper;

[0016]FIG. 2 is a side view of the overall unit of the apparatus of FIG.1 in a second phase of operations for wrapping a ream of paper (someparts being omitted to make the drawing easier to read);

[0017]FIG. 3 is a side view of an overall unit of the apparatus of FIG.2 in a third phase of operations for wrapping a ream of paper;

[0018]FIG. 4 is a side view of an overall unit of the apparatus of FIG.2 in a fourth phase of operations for wrapping a ream of paper;

[0019]FIG. 5 is a side view of an overall unit of the apparatus of FIG.2 in a fifth phase of operations for wrapping a ream of paper;

[0020]FIG. 6 is a side view of an overall unit of the apparatus of FIG.2 in a sixth phase of operations for wrapping a ream of paper;

[0021]FIG. 7 is a side view of an overall unit of the apparatus of FIG.2 in a seventh phase of operations for wrapping a ream of paper;

[0022]FIG. 8 is a side view of an overall unit of the apparatus of FIG.2 in an eighth phase of operations for wrapping a ream of paper;

[0023]FIG. 9 shows some details of the apparatus shown in FIG. 7 on anenlarged scale;

[0024]FIG. 10 is a plan view of the overall unit of the apparatus ofFIG. 2;

[0025] FIGS. 11 to 18 are perspective views of a ream of sheets and arelative wrapping sheet in different phases of the method of the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

[0026] In FIG. 1, an apparatus for wrapping reams 11 of sheets of paper12 in relative wrapping sheets 14 to form packs 15, one of which isshown in FIG. 15, is shown overall by 10.

[0027] In further detail, and with reference to FIG. 11 as well, eachream 11 comprises a certain number of sheets 12 which are stacked andaligned on top of one another in order to provide the ream 11 with theshape of a prism with a rectangular base and a height H.

[0028] The ream 11 has two parallel and opposing faces 16 a, 16 b, eachof which is defined by an end sheet 12 of the ream 11. The ream 11 isfurther defined by two front faces 17 a, 17 b which are parallel withone another and perpendicular to the base face 16 b and two lateralfaces 18 a, 18 b which are also parallel to one another andperpendicular to the base face 16 b.

[0029] The rectangular prism shape of the ream 11 depends on thesuperimposition of the sheets 12, which are in contact with one anotheras a result of the friction between the adjacent sheets 12 of the ream11, when the forces acting on the ream 11 are contained within certainpredetermined values.

[0030] In FIG. 1, the apparatus 10 firstly comprises a frame T adaptedto support the various units making up this apparatus 10 (see below).

[0031] Looking in more detail at the apparatus 10 of FIG. 1, and movingfrom the left to the right of the drawing, there is a unit 20 forforming and feeding the reams 11 along X and along a path P. The unit 20firstly comprises a device 21 for locking and forming the reams 11 so asfully to align the sheets 12 on one another.

[0032] Using known means, the device 21 is raised until it reaches theposition shown in dashed lines in FIG. 1 in order to enable thesuccessive feeding of the ream 11 along the path P.

[0033] The unit 20 further comprises a lower belt conveyor 22 woundabout a pair of pulleys 22 a, 22 b, and an upper belt conveyor 23 alsowound, in turn, about a pair of pulleys 23 a, 23 b. While the conveyor22 is fixed with respect to a reference plane RIF, the upper conveyor 23may be moved by a device (not shown) in a direction shown by Y andperpendicular to this reference plane RIF.

[0034] After the ream 11 has been formed by the action of the device 21,the upper conveyor 23 is lowered so that the ream 11 is tight betweenthe lower conveyor 22 and the upper conveyor 23.

[0035] The reams 11, as they are formed, are fed from the unit 20 to aunit 30 for supplying wrapping sheets 14 (see FIG. 11 as well) and to afolding unit 40.

[0036] The components of the units 30 and 40 will be described infurther detail below.

[0037] It will be appreciated that, although the present description ofthe particular embodiment shown in the accompanying drawings makesexplicit reference to sheets of wrapping paper 14 taken individually,i.e. cut from a spool (not shown), there is nothing to prevent thepresent invention from being applied to a spool of paper which, by meansof an adapted supply unit (not shown), is fed directly to the foldingunit 40.

[0038] As shown in FIG. 1, the motorisation of the pulleys 22 a and 23 arelating respectively to the lower conveyor 22 and the upper conveyor 23is controlled by an electronic control unit 100. This regulationirrespective of the speed of rotation of the electric motors (not shown)of the pulleys 22 a and 23 a is necessary to provide identical drivespeeds along the rectilinear sections of the conveyors 22 and 23.

[0039] This is also necessary to prevent, when the type of belt used inthe conveyors 22, 23 is changed or as a result of the wear of the belts(which causes their thickness to vary), different peripheral speeds inrespect of the two conveyors 22, 23. Were this to happen, there would berelative displacements of the upper face 16 a with respect to the lowerface 16 b, causing the relative ream 11 to come out of alignment.

[0040] Looking now at the unit 30 for supplying wrapping sheets 14 (FIG.1), it will be appreciated that this unit 30 comprises a lower gripperunit 31 and an upper gripper unit 32 which hold the wrapping sheet 14taut in a position substantially parallel to Y and thereforeperpendicular to the path P and the plane RIF. The lower gripper unit 31and the upper gripper unit 32 are on opposite sides with respect to theplane RIF. The unit 30 further comprises a vertical wall 33 on which aportion of the wrapping sheet 14 bears.

[0041] As will be described below in detail, the wall 33 and the devicesmaking up the folding unit 40 form a mandrel for wrapping the ream 11.

[0042] The folding unit 40 comprises (see FIG. 9 as well) a lowerfolding member 41 and an upper folding member 42 also disposed onopposite sides with respect to the plane RIF.

[0043] The two folding members 41, 42 are moved synchronously by anarticulated quadrilateral mechanism 43 from a first retracted position(with respect to the path P) shown, for instance, in FIG. 1, to a secondforward position (again with respect to the path P) shown, for instance,in FIG. 2.

[0044] In the forward position (FIG. 2), the folding member 41 is inabutment on a block 44, while the folding member 42 enters into contractwith a brush member 45 whose bristles are disposed perpendicular to theplane RIF. The block 44 is, moreover, substantially L-shaped, with avertical portion 44 a perpendicular to the plane RIF and a shorterhorizontal portion 44 b lying in this plane RIF.

[0045] As shown in FIG. 2, moreover, when the ream 11, under the actionof the conveyors 22, 23, comes into contact with the wrapping sheet 14,the lower gripper unit 31 is raised in the direction of the plane RIF,while the upper gripper unit 32 is lowered, again in the direction ofthe plane RIF. The wrapping sheet 14 is caused to adhere to the face 17a (see FIG. 11 as well), however, by the pull of the gripper units 31,32 on this wrapping sheet 14.

[0046] As shown in FIG. 2, during this phase, the wrapping sheet 14, aswell as adhering to the face 17 a, bears partially on the faces 16 a, 16b, assisted by the fact that the simultaneous feed (along the path P) ofthe mechanism 43 has made it possible to form a lower fold P1 (see FIG.11 as well) as a result of the fact that the member 41 has borne on thevertical portion 44 a of the block 44, and to form an upper fold P2 as aresult of the contact of the member 42 with the brush member 45.

[0047] Obviously, as shown in FIG. 11 as well, the fold Pi is formed atthe location of the edge of intersection between the lower face 16 b ofthe ream 11 and the front face 17 a of this ream, while the fold P2 isformed at the location of the edge of intersection between the upperface 16 a of the ream 11 and the front face 17 a.

[0048] As shown in FIG. 3, the ream 11 is conveyed further by theconveyors 22, 23 such that portions of growing amplitude of the wrappingsheet 14 bear on the faces 16 a, 16 b of the ream 11. The operation to“smooth” the wrapping sheet 14 is assisted by the action of thehorizontal portion 44 b of the block 44 on the lower face 16 b of theream 11 lying in the plane RIF, while the brush device 45 carries outthe above-mentioned smoothing operation on the upper surface 16 a ofthis ream 11.

[0049]FIG. 4 shows the situation in which the ream 11 continues to befed under the action of the conveyors 22, 23, with the wrapping sheet 14which winds ever further about this ream 11.

[0050]FIG. 4 also shows a configuration of the apparatus 10 in which theream 11, partially covered by the wrapping sheet 14, is taken up by adistancing unit 50.

[0051] This unit 50 comprises, in turn, a lower belt conveyor 51, whichis fixed and lies in the plane RIF, and an upper belt conveyor 52 ofretractile type. The lower conveyor 51 comprises a belt and a pair ofpulleys 51 a, 51 b. The upper conveyor, however, comprises a belt 52 awound about a series of four pulleys 52 b-52 e. In FIG. 4, the upperconveyor 52 is fully deployed, i.e. the pulleys 52 b and 52 d aredisplaced, by means which are not shown, towards the folding unit 40 soas to locate the ream 11, which is then taken up by the conveyors 51,52.

[0052] In FIG. 5 (see FIG. 12 as well), the ream 11 is fed only by theunit 50, while the feed unit 20, which is no longer in contact with theream 11, is again opened by distancing the conveyor 23 from the conveyor22, and is ready for the transport of a new ream 11 (not shown). At thesame time, as shown in FIG. 5, the pulleys 52 b and 52 d (position shownin dashed lines) are displaced along X reducing the longitudinal bulk ofthe conveyor 52 for a purpose that will be explained below.

[0053] The upper portion of the wrapping sheet 14 has been released bythe upper gripper unit 32 (which, in the meantime, takes up anothersubsequent sheet 14 in order to wrap the subsequent ream 11) and bearscompletely on the face 16 a of the ream 11 as a result also of theaction of the brush device 45. The lower portion of the wrapping sheet14 is also no longer retained by the lower gripper unit 31 (which, inthe meantime, takes up another successive wrapping sheet 14 in order towrap the successive ream 11). The lower portion of the wrapping sheet 14then completely covers the lower face of the ream 11 and lies on thehorizontal portion 44 a of the block 44.

[0054] In the phase shown in FIG. 5, profiting from the fact that theconveyor 52 is in the retracted position, the outer surface of the upperlimb of the wrapping sheet 14 which, as mentioned above, is wound on theupper face 16 a of the ream 11, is sprayed with an adhesive substance.The adhesive substance is sprayed by a spray device 60 whoselongitudinal axis is perpendicular to the plane RIF.

[0055] Moreover, a folding unit 70 is disposed between the block 44 andthe conveyor 51 and comprises a wall 71 adapted to slide, moved bydevices which are not shown, into an interstice 72 provided on thesurface RIF.

[0056] The interstice 72 is immediately downstream of the block 44 inthe direction of the path P.

[0057] The movement of the wall 71 is a conventional guillotine movementwithin the interstice 72 and is adapted to urge the end portion of thelower limb of the wrapping sheet 14 upwards. The wall 71 moves along Y(FIG. 6).

[0058] As shown in FIG. 7, this end portion of the limb is retained foran instant in a vertical position by a retaining unit 80.

[0059] The retaining unit 80 in turn comprises a stop 81 and a brushdevice 82 which, as can be seen from a comparison of FIG. 6 with FIG. 7,is adapted to move along Y and to rotate about R.

[0060] In the take-up position of the lower limb of the wrapping sheet14, the brush device 82, moved by adapted mechanisms (not shown), hasbeen vertically displaced and has rotated such that this lower limb isretained between the stop member 81 and the bristles of the brush device82.

[0061] In an embodiment which is not shown, the function of retainingthe lower limb of the wrapping sheet 14 is performed by a vacuumretaining device (not shown).

[0062]FIG. 8 shows the phase in which the lower limb has been releasedby the retaining unit 80, while the brush device 45 is displaced along Xin order to “smooth” the lower limb on the outer surface of the upperlimb of the wrapping sheet 14 which, as mentioned above, has alreadyreceived the adhesive substance from the spray device 60 (FIG. 5).

[0063] The “first wrapping tube” PT has been formed in this way (seeFIG. 13 as well) and is then subject to the successive folding andadhesive operations which will be explained below in further detail.

[0064] In order to simplify the description, it will now be better toturn to the plan view of FIG. 10 in which the same reference numeralshave been used for members that can be readily recognised and are alsoshown in the other Figures.

[0065] By displacing some devices, it is possible to adapt the apparatus10 to different formats of reams 11.

[0066]FIG. 10 in particular shows the configuration of the apparatus 10used to process small-format reams 11.

[0067] Along the path P, the first tube PT (see FIG. 14 as well)encounters two abutments 53 disposed symmetrically on opposite sides ofan axis of longitudinal symmetry A (FIG. 10).

[0068] The portions of the first tube PT projecting with respect to thebulk of the ream 11 encounter the abutments 53 and are folded to formtwo front flaps NAS1 (FIG. 14) and four relative tongues LIN1′, LIN1″,LIN2′ and LIN 2″.

[0069] In order, however, to form two rear flaps NAS2 (FIG. 15), twoarms 54 (FIG. 10) are used, which, by rotating about an axis 55(perpendicular to the plane of the sheet as shown in FIG. 10) and movingalong X, fold the wrapping sheet 14 in the desired manner. At the end ofthe movement to form the rear flaps NAS2, each of the two arms 54 bearson the respective abutment 53.

[0070] In other words, the arms 54 are arms that “follow” the ream 11,partially wound about by the wrapping sheet 14, along the path P.

[0071] As shown in FIG. 10, the distancing unit 50 is followed along thepath P by a removal unit 90 (see FIG. 1 as well) in turn comprising alower belt conveyor 91 of known type.

[0072]FIGS. 1 and 10 also show two pressure devices 92 and 93 disposedin series with one another.

[0073] The pressure device 92 (FIG. 1) in turn comprises a pressuremember 92 a moved by an articulated parallelogram mechanism 92 b.Similarly, the pressure device 93 comprises a pressure member 93 a movedby an articulated parallelogram mechanism 93 b.

[0074] The pressure devices 92, 93 are adapted to keep the ream 11,already partly wrapped, under pressure on exit from the distancing unit50. The pressure exerted by the pressure members 92 a and 93 a on theupper face of the partial wrapping facilitates the mutual adhesion ofthe limbs of wrapping paper 14 superimposed on the upper face 16 a ofthe ream 11.

[0075] Prior, however, to leaving the distancing unit 50, the tonguesLIN1″ and LIN2″ are folded downwards by means of a helical foldingdevice 94 in order to form the partial wrapping shown in FIG. 16.

[0076] Moreover, as can be readily seen from FIGS. 1 and 10, a freespace 95 is provided between the conveyor 51 and the conveyor 91, whoseupper faces both lie in the plane RIF, at the location of which spacetwo spray devices 96, adapted to spray adhesive substance on the innersurfaces of the tongues LIN1′ and LIN2′, as shown in FIG. 16, arepositioned on opposite sides with respect to the axis A. Thelongitudinal axes of the two spray devices 96 are perpendicular to theplane RIF.

[0077] The positioning of the spray devices 96 at the location of thefree space 95 is important, as this prevents glue from being sprayed andbeing deposited in an undesired manner on the conveyors 51 and 91 aswell, with the adverse effects that this would entail.

[0078] At the start of the removal unit 90 there are two helical foldingdevices 97 of known type, disposed on opposite sides with respect to theaxis A and at an equal distance from this axis A.

[0079] With reference to FIG. 17 as well, the folding devices 97 areadapted upwardly to fold the tongues LIN1′ and LIN2′, which are thenglued on the tongues LIN1″ and LIN2″, already folded during the phaseshown in FIG. 16.

[0080] Continuing its travel along the path P, the partially wrappedream P reaches another pair of helical folding devices 98 of known type,also disposed on opposite sides with respect to the axis A andequidistant from this axis A.

[0081] These folding devices 98 are adapted further to fold the end limbof the two lower tongues LIN1′ and LIN2′ onto the upper face 16 a of theream 11 in order to form two folded edges B (FIG. 18) glued on the outersurface of the upper portion of the first tube PT. The desired pack 15is therefore provided.

[0082] In order to improve the transport of the already partly wrappedreams 11, means (not shown) are provided in order to create a vacuum. Inthis respect, these means are pneumatically connected with two boxes 99a and 99 b which are respectively disposed below the portions of theconveyors 51, 91 that lie in the plane RIF. It will be appreciated thatthe belts used to form these conveyors 51, 91 have a plurality of holesF by means of which the desired locking by suction of the already partlywrapped reams 11 and the packs 15 is performed, which reams and packsare than removed from the apparatus 10 for subsequent use.

[0083] The electronic control unit 100, in addition to controlling thespeed of the conveyors 22, 23, is able to regulate all the otheroperations performed by the apparatus 10. In particular, for the reasonsalready discussed above with reference to the conveyors 22, 23, thiscontrol unit 100 is adapted to control the speeds of the belts of theconveyors 51 and 52.

[0084] The advantages of the apparatus and method of the presentinvention are as follows:

[0085] reduction of the overall length of the apparatus, having causedthe unit for forming the initial wrapping to coincide with the unit forfolding the lateral flaps;

[0086] greater compactness with a substantial reduction of theproduction costs of the apparatus;

[0087] possibility of processing reams of small format as a result ofthe use of a retractile conveyor that comes into contact with the firstwrapping tube in order to cause the displacement of this first wrappingtube to the other folding and adhesion units.

1. An apparatus (10) for wrapping reams (11) of paper (12), whichapparatus (10) comprises: (a) a unit (20) for forming and feeding thereams (11) along a path (P); (b) units (30, 40, 50, 60, 70, 80) forforming the first tube (PT) for wrapping the ream (11) of paper with awrapping sheet (14); (c) devices (53, 54) for the lateral folding of thefirst tube (PT) in order to form lateral flaps (NAS1, NAS2) so as toobtain two lower tongues (LIN1′, LIN2′) and two upper tongues (LIN1″,LIN2″); (d) folding devices (94) for the upper tongues (LIN1″, LIN2″);(e) spray devices (96) adapted to spray an adhesive substance on theinner surfaces of the lower tongues (LIN1′, LIN2′); (f) devices (97, 98)for folding the lower tongues (LIN1′, LIN2′) over the respective uppertongues (LIN1″, LIN2″), already folded, in order to obtain a pack (15)containing the ream (11); the apparatus (10) being characterised in thatthe units (30, 40, 50, 60, 70, 80) for forming the first tube (PT) areadjacent to the devices (53, 54) for the lateral folding of the firsttube (PT) in order simultaneously to form the lateral flaps (NAS1,NAS2).
 2. An apparatus (10) as claimed in claim 1, in which the foldingunit (40) comprises a lower folding member (41) and an upper foldingmember (42) moved synchronously by actuation means (43) from a firstretracted position to a second forward position, in which forwardposition the lower folding member (41) is in abutment on an block (44)and the upper folding member (42) is in abutment on a brush member (45).3. An apparatus (10) as claimed in claim 2, in which the actuation means(43) comprise an articulated quadrilateral mechanism (43).
 4. Anapparatus (10) as claimed in claim 2, in which the block (44) issubstantially L-shaped, with a vertical portion (44 a) perpendicular tothe path (P) and a horizontal portion (44 b).
 5. An apparatus (10) asclaimed in claim 1, in which the folding unit (70) comprises a wall (71)adapted to slide in the manner of a guillotine into an interstice (72)in order to urge the end portion of the lower limb of the wrapping sheet(14) upwards.
 6. An apparatus (10) as claimed in claim 1, in which theunit (80) comprises a stop (81) and a brush device (82), this brushdevice (82) being adapted to be displaced from a first disengagedposition to a second position of engagement with the stop (81), wherethe lower limb of the wrapping sheet (14) is taken up, and in which thebrush device (82), in order to reach this second position starting fromthe first position, is vertically displaced and rotates.
 7. An apparatus(10) as claimed in claim 1, in which the unit (80) comprises a vacuumretaining device adapted to perform the function of retaining the lowerlimb of the wrapping sheet (14).
 8. An apparatus (10) as claimed inclaim 1, in which the unit (50) comprises a lower belt conveyor (51) andan upper belt conveyor (52) of the retractile type, which assumes theretracted position in order to enable the apposition of an adhesivesubstance on the wrapping sheet (14) by means of a spray device (60). 9.An apparatus (10) as claimed in claim 1, in which the lateral foldingdevices (53, 54) for the first tube (PT) comprise follower arms (54) inorder simultaneously to form the flaps (NAS1, NAS2).
 10. An apparatus(10) as claimed in claim 1, in which an electronic control unit (100) isprovided and is adapted to control all the functions of the otherdevices included in this apparatus (10), the electronic control unit(100) being in particular adapted independently to control the speeds ofthe belts of the conveyors (22, 23, 51, 52) in order to have identicalspeeds of advancement of the reams (11) along the rectilinear sectionsof the conveyors (22, 23) and (51, 52) respectively.
 11. An apparatus(10) as claimed in claim 1, in which a removal unit (90) is disposeddownstream of the distancing unit (50), a free space (95) being providedbetween this distancing unit (50) and removal unit (90), at the locationof which space two spray devices (96) adapted to spray an adhesivesubstance on the inner surfaces of the tongues (LIN1′, LIN2′) arepositioned.
 12. A method of wrapping reams (11) of sheets (12), in whicheach ream (11) is composed of sheets (12) stacked on one another to forma prism with a rectangular base and a predetermined height (H), whichmethod is characterised in that it comprises the following stages: (a)formation of the reams (11) and feeding of these reams (11) along a path(P); (b) formation of a first wrapping tube (PT) for the ream (11) ofpaper with a wrapping sheet (14); (c) lateral folding of the first tube(PT) in order to form lateral flaps (NAS1, NAS2) so as to obtain twolower tongues (LIN1′, LIN2′) and two upper tongues (LIN1″, LIN2″), theformation of the first tube (PT) being adjacent to the folding of thisfirst tube (PT) in order simultaneously to form the lateral flaps (NAS1,NAS2); (d) folding of the upper tongues (LIN1″, LIN2″); (e) appositionof an adhesive substance on the inner surfaces of the lower tongues(LIN1′, LIN2′); (f) folding of the lower tongues (LIN1′, LIN2′) over therespective upper tongues (LIN1″, LIN2″), already folded, so as to obtaina pack (15) for the ream (11).